The integration of multiple power transistors and a microcontroller in a small and thin package presents several challenges. For example, multi-phase brushless DC motors require high current (e.g. between 70 A to 120 A), operate at high temperature (e.g. above 150° C.), and consume significant power (e.g. up to 500 W). A half bridge driver for such an application generates significant heat that must be dissipated by the package. Conventional multi-phase half bridge drivers are implemented by attaching the half bridge power transistor dies and the corresponding controller die to a printed circuit board (PCB). Such a solution has a large footprint and provides no built-in cooling features. Such a conventional board-based implementation of a multi-phase half bridge driver also suffers from voltage spikes and higher levels of EMI (electromagnetic interference), due to high inductance connections between the dies and the board.
Hence, there is a need for an improved multi-phase half bridge driver package solution having a smaller footprint, better heat dissipation characteristics and lower inductance.